when my i restart my rasberry pi. pm2 goes into an error state. and magic mirror won’t start again.

{ Error: ENOENT: no such file or directory, open ‘package.json’
at Object.fs.openSync (fs.js:660:18)
at Object.fs.readFileSync (fs.js:565:33)
at Object. (/home/pi/MagicMirror/js/app.js:15:32)
at Module._compile (internal/modules/cjs/loader.js:654:30)
at Object.Module._extensions…js (internal/modules/cjs/loader.js:665:10)
at Module.load (internal/modules/cjs/loader.js:566:32)
at tryModuleLoad (internal/modules/cjs/loader.js:506:12)
at Function.Module._load (internal/modules/cjs/loader.js:498:3)
at Function._load (/usr/lib/node_modules/pm2/node_modules/@pm2/io/build/main/metrics/httpMetrics.js:172:43)
at Module.require (internal/modules/cjs/loader.js:598:17)
errno: -2,
code: ‘ENOENT’,
syscall: ‘open’,
path: ‘package.json’ }

how do i fix this?